Waheed gives four steps for detecting CNV with OCT angiography

KOLOA, Hawaii — Even though fluorescein angiography plus high-resolution optical coherence tomography is the gold standard for detecting neovascularization, OCT angiography does a better job than FA in some situations, Nadia K. Waheed, MD, said at Retina 2017.

However, interpreting the OCT angiography findings can be time consuming, with the reader needing sometimes to scroll through entire data sets.

Nadia K. Waheed

In cases of suspected choroidal neovascularization, Waheed offered guidance to help OCT angiography users interpret the data.

First, she said, make sure to look at the right spot using the 3 by 3 scan to provide the highest resolution.

“The second step that I like to do is to look at the en face OCT angiography image,” Waheed said. “These are fast and automatically generated. ... You’re specifically looking at the outer retina and the choriocapillaris.”

The third step is to look at the segmentation lines. Looking at the segmentation lines is important for avoiding false-positives when suspected CNV is seen and avoiding false-negatives when CNV is not seen.

Regarding false-positives, the two things to look out for are geographic or macular atrophy and projection artifact, she said.

“The fourth step is to look at the en face intensity image,” she said, because it provides a map of where the OCT signal is not penetrating through into the choriocapillaris.

“It’s really hard to miss CNV when you follow these four steps,” she said.

Reference:

Waheed NK. OCT angiography in wet age-related macular degeneration. Presented at: Retina 2017; Jan. 16-20, 2017; Koloa, Hawaii.

Disclosure: Waheed reports she receives consulting fees from Genentech, Regeneron and Zeiss and is on the speaker's bureau for Nidek and Optovue.